“Brake-by-wire” brake systems are being used ever more frequently in automotive technology. In the case of these brake systems, the brake can be “independently” actuated on the basis of electronic signals without any active input on the part of the vehicle driver. These electronic signals can, for example, be emitted by an electronic stability program ESC or an adaptive cruise control ACC. In addition, if a braking effect that is requested by the vehicle driver by way of a brake pedal actuating force is achieved, for example, by switching an electric vehicle drive into a generator operation, it is possible to omit fully or partially an actuation of the brake system.
Brake systems and/or braking systems of this type that are embodied in an electrohydraulic manner usually comprise in addition to the hydraulic actuating device a simulation device into which brake fluid and/or a pressure medium is directed from the actuating device as the brake pedal is actuated. The simulation device in this case usually comprises an elastic simulator element, for example a spring, that is stressed as the pressure medium is introduced, for example by way of a piston that can be moved as a result of the pressure medium being introduced. It is possible in this manner on the one hand to achieve a reproducible relationship between the pedal travel and the braking torque. On the other hand, an attempt is made thereby to convey to the driver a pedal sensation that is known from conventional hydraulic brake systems. The processes of designing and constructing a pedal travel simulator of this type represent a complex challenge.
The object of the present invention is to provide a vehicle brake system of this type, the operational reliability of which can be tested during the normal brake function and which vehicle brake system conveys to the driver a pedal sensation known from conventional hydraulic brake systems. In particular, the pedal sensation is to be improved with respect to known brake systems of this type. Furthermore, a method for operating a brake system of this type is to be provided.